DE2052822C3 - Process for the preparation of N, N, N ', N'-tetraacetylethylenediamine - Google Patents

Description

The invention relates to a process for the preparation of N.N.N ^ N'-tetraacetylethylenediamine by reaction of diacetylethylenediamine with acetic anhydride and ketene.

It is known that one can use tetraacetylethylenediamine obtained by reacting diacetylethylenediamine with ten times the amount by weight of acetic anhydride can (Recueil des Travaux Chimiques des Pays-Bas, 30,183-185, [1911]). The process gives unsatisfactory results Yields of the end product. The solubility of tetraacetylethylenediamine in such reaction mixtures is particularly high, which leads to a reduction in yield and an uneconomical, distillative Forcing the processing of the mother liquors

According to DE-OS 1910 300 tetraacetylethylenediamine is obtained when ethylenediamine or Diacetyläthylendiamin at 40 to 100 ⁰ C in the presence of orthophosphoric acid as a catalyst and optionally in the presence of a sulfur compound in an organic, inert solvent e.g.,. B. acetone, chloroform or ethyl acetate, reacts with ketene. This process has the following disadvantages: The solubilities of the reaction components at the specified temperatures are very low. Therefore, larger amounts of solvent have to be used and relatively dilute solutions are formed, for example in Example 2 15% by weight solids, Example 4 4.4% by weight solids. In this way, the process requires relatively large reactors and thus high investment costs, large amounts of energy for heating and evaporation of the solvent and thus high energy costs. Furthermore, the space-time yields are small; in Example 6 (continuous experiment) they only reach 15.2 to 19.2 kg / m ³ h. The ketene conversion and thus the yield of the end product, based on the ketene used, is unsatisfactory. Only part of the ketene is absorbed, the rest emerges from the reaction space and takes with it large proportions of the solvent (contamination of the exiting ketene, solvent losses and possibly costs for the condensation). The solubility of the Tetraacetyläthylendiamins in the organic solvents is still considerable, even at low temperature, so that good yields to obtain freeze (Example 1 -8 ^e C - Example 5 2 ° C) must or even remove the solvent by evaporation (Example 3). These measures require additional costs and are necessary in order to avoid further, substantial losses in yield.

It has now been found that Ν, Ν, Ν ', Ν'-tetraacetylethylenediamine by acetylation of Ν, Ν- or N.N'-diacetylethylenediamine advantageously obtained when 1 mol of the diacetylethylenediamine at 40 to 150 ⁰ C with 1 to 50 moles of acetic anhydride and 1 to 3 moles of ketene are converted

The implementation can be represented by the following formulas:

H H

N-CH ₂ CH ₂ -N + (CH ₃ CO) ₂ O + CH ₂ = C = O

H ₃ CC = OO = C-CH ₃

C-CH ₃

N - CH ₂ - CH ₂ - N

H ₃ CC

Il
ο

C-CH,
O

H ₃ CC

Il

C-CH ₃

N-CH ₂ -CH ₂ -N H ₃ CC C-CH ₃

+ CH ₃ COOH

The process according to the invention provides ethylenediamine in better yield, space-time-off comparison Surprisingly, there are none among the known methods on simpler prey and purity and more economical way Ν, Ν, Ν ', Ν'-tetraacetyl catalysts and solvents and thus none

special purification operation or distillation di; s Reaction mixture necessary, the acetic acid formed is again the starting material with ketene Acetic anhydride.

The starting materials acetic anhydride and _{ketane are mixed with the starting material N 1} N- or preferably N.N'-diacetylethylenediamine in a stoichiometric amount or in excess, preferably in a ratio of 2J5 to 50, in particular 2 to 5 moles of acetic anhydride and 1 to 3 moles of ketene 1 mol of diacetylethylenediamine, converted. The preparation of the tetraacetyl compound takes place with the formation of Ν, Ν, Ν'-triacetylethylenediamine as intermediate product. If less than stoichiometric amounts of ketene and acetic anhydride are used, mixtures with a proportion of 1 to 25 wt. % Triacetyl compound. With a more than six-fold excess of acetic anhydride alone over the stoichiometric amount or 0.2-fold excess of ketene with the stoichiometric amount of acetic anhydride, the result of the reaction is the pure tetraacetyl compound without substantial amounts of triacetyl compound. A reaction with smaller amounts of the two starting materials results in mixtures of the two end products mentioned with proportionally increasing triacetyl compound content, the lower the proportion of these starting materials

For the process according to the invention, the ketene can be used in pure form or in the form of crude ketein, as is the case after the cleavage of acetic acid, after the addition of ammonia and cooling, e.g. B. to 10 ° Q. This raw ketene can still contain impurities such as methane, carbon dioxide, carbon monoxide, ethylene, propene, butadiene, butyne, hydrogen and especially water, acetic acid and acetic anhydride vapors, e.g. in a composition of 80.5 vol. % Ketene, 2% by volume of acetic acid / acetar (hydride vapor, 16.5% by volume of gaseous impurities (inert gas) and optionally 0.5% by weight of salts, e.g. ammonium phosphate The ketene in crude or purified; -ter form is usually at a temperature between -30 and +40 ⁰ C, preferably between -10 and + 10 ⁰ C, and at a pressure of 0.05 to 0.15, preferably from 0.05 to 0.2 at

The reaction is generally carried out at a temperature between 40 and 150 ^° C., preferably between 90 and 150 ^° C., in particular between 135 and 147 ° C., under pressure or preferably without pressure, continuously or batchwise. Solvents are not necessary for the process; however, appropriate organic solvents which are inert under the reaction conditions, such as aromatic carbons, for example toluene, chlorinated hydrocarbons, for example trichlorethylene, chloroform, can be added.

The reaction can be carried out in the liquid phase or in the vapor phase. Used with preference for the process according to the invention, distillation plants, in particular packed columns or trays Columns such as sieve tray, Oldershaw, glass tray, bell tray and valve tray columns. Advantageous tray columns are used which have a mass flow of 0.01 to 0.6 parts by weight hourly into the column Allow ketene entering per part by weight of liquid in the column. In the bubble tray columns is the ratio of weir height to diameter from 0.2 to 0.4, for ball valve tray columns and sieve tray * Columns are hole diameters from 5 to 15 mm, sphere diameters from 8 to 30 mm and distances from the bottom from 300 to 800 mm preferred

The reaction can be carried out as follows: Diacetyläthylendianün is in acetic anhydride.

s dissolves, the mixture to reaction temperature, expedient 140 to 145 ° C at normal pressure, and the temperature 1 to 8 hours, preferably 1.5 to 3 hours Hours, held. The rising steam is condensed in a reflux condenser and runs through empty tube, the bottoms of a tray column or a stirred tank back into the reaction mixture return.

At a point near the liquid phase, ketene is expediently in the column or in the

A stirred tank is introduced.In a preferred procedure, tray columns are used and the ketene is introduced directly into the condensate of several trays or, in particular, into the condensate of a tray in the middle of the column.The introduction of the ketene into the liquid reaction mixture of the distillation still is possible, but in comparison to the introduction less indicated in the vapor space and especially in the condensate of the column or the distillation plant in order to achieve an optimal yield of end product. The speed of the Keteneinleitung is suitably adjusted according to the color of the condensate in yellowing the Ketenzufuhr is throttled The temperature at the Keteneinleitungsstelle is advantageously from 40 to 140 ⁰ C, preferably 90-137 ⁰ G. After completion of the reaction, the solution is suitably in order to achieve Small crystals cooled as quickly as possible to 15 ° C, whereby the end product separates. The smaller the crystals are, the cleaner they are and the easier they can be washed. The end product is then isolated in the usual way, e.g. B. the reaction mixture is filtered appropriately the filter material with the same to 3 times the amount by weight of acetic anhydride or the same amount of distillate of the mother liquor washed and dried. You can also wash with cold water at 0 to 5 ° C. The mother liquors remaining after the end product has been separated off can be used in the process according to the invention as a reaction medium for further batches, which also means that the still unconverted proportions of the starting materials can be used economically

The compounds which can be prepared by the process of the invention are valuable starting materials for Manufacture of textile auxiliaries, cleaning agents

so and pesticides. They can be used as activators, e.g. B. in an amount of 0.1 to 15 wt .-%, Detergents or bleaches are added, which in addition to an anionic or cationic or a nonionic surface-active compound contain an active oxygen donating compound. They can also be used for the manufacture of viscose rayon preparations. Regarding the For use, we refer to the publications mentioned.

The parts given in the following example are parts by weight.

example A bubble-cap tray column also serves as the apparatus

10 floors each with a bell and a reflux condenser.

The ratio of weir height to column diameter

is 0.3. The starting mixture consists of 513 parts

N.N'-Diacetyläthvlenediamine and 1224 parts of acetic acid

reanhydride. The geroish is heated to the boil, the bubble-cap bottoms film and a constant reflux occurs. After 15 minutes, the introduction of ketene is started. 180 parts of ketene are introduced into the condensate at a rate of 50 to 80 parts by weight / h over the course of 3 hours at the 4th tray from the bottom. The ketene conversion is 94.1% of theory. The temperature in the condensate of the two is 140 to 145 ° G. After 3 hours, the mixture is cooled to 16 ° C., tetraacetylethylenediamine crystallizing out. The crystals are filtered off with suction and washed with 1000 parts of acetic anhydride. Likewise, the crystals are separated off, which are obtained by evaporating the mother liquor to 300 parts by volume. The end product is at 80 ⁰ C and 16 Torr 10 hours dried to give 775 parts of end product, mp. 153-155 ° C. A 3gewichtsprozentige chloroform solution exhibited a color index of 12 Hazen. The yield is 95.5% of theory, the space-time yield

ίο 211kg / m ³ h.

Claims (1)

Claim: Process for the preparation of Ν, Ν, Ν ', Ν'-tetraacetyiäthylenediamine by acetylation of N ₁ N- or N.N'-diacetylethylenediamine, characterized in that 1 mol of the diacetylethylenediamine at 40-150 "C with 1 to 50 mol Acetic anhydride and 1 to 3 moles of ketene converts IO